A tade more briteness - Jolida 302b. Tubes?

If you are running stock tubes, then absolutely, you can get more open highs with a tube change. Cabling can also bring out more in the high end as well. I'd start with the tubes at the source, and even a power cable on the source. When I had the Jolida JD-100 (is that the model you have?), it really came to life (much better frequency extension, less constriction on the music) with a good pair of NOS tubes and an upgraded power cord. Lots of info in the archives on various options for that player. The other source of constriction is often the interconnect cables. If you are using Signal, consider trying something like Analysis Plus Solo Crystal, Luminous Audio Synchestra, Z-Squared Au/Au, etc. When it comes to cabling, my recommendation is to keep an open mind, pick a price limit with which you are comfortable, and if you buy used, you can always re-sell (at no loss) those that don't work for you.
Very nice system. Enjoy!

Boa2, thanks for the very senceable advice! What about changing tubes on the Jolida 302b? Yes, I have the JD 100.

Gretsch6120, I think I posted this in your other thread, but this should do:

Powertubes: SED (Svetlana) EL43 or JJ E34L
I liked the SED a bit more than the JJ, smoother highs, a little softer bass, deeper soundstage. However, I had a couple of SED failing after very short time, with the JJ being very stable.

Preamp and driver tubes (my favorite combination)
12AX7 1970s Tesla E83CC Frame Grid gold pin
12AT7 1980s Mullard CV4024
Altnernatively the EH 12AX7 gold pin worked quite well also. Not as nice as the Tesla, but still good.

Preamp and driver tubes (alternative combination)
12AX7 1980s Jan GE 5751
12AT7 19??s BRIMAR 6060 T-Series Black Plates

The preamp tubes will have probably the greatest effect on the sound. The Tesla E83CC NOS or alternatively the EH 12AX7 Gold pin should do the trick for extended highs. Also, you could combine the Tesla with the Brimar 6060 and get a really detailed, lively and a little forward sounding combination. (A little too much in my system)

Good luck tube rolling,
Rene